Let's say I have some parameter on the device which couldn't be modulated by "keyboard tracking" modulation source natively. So I wrap the device with combi and in the programmer I select the particular parameter. But in the list of the modulation sources are only combi controllers, performance controllers and CV inputs.

So how I would assign the "keyboard tracking" to modify my desired parameter ? Is there some device which sends out CV signal values based on MIDI notes ? I believe there is some simple solution perhaps with some stock device.

Just grab some device which can provide "MIDI note" as modulation source and CV output as destination. For example, Thor. Include it in the combi and connect the CV output of Thor into CV input of Combi.

:Haha, we wrote the same answer at the same time Timmy Crowne ...thanks.

Just small tip on the top of that:

Very handy device is the "Janitor CV Shaper" utility (it's free). It allows you to manipulate CV signals straight from the front panel, no back panel switching needed for modulation amount, etc. It's good device for adjusting the basics of the CV signals, very simple, straightforward device.

In this case I use "Scale" knob for keyboard tracking modulation amount and "Offset" knob for initial value of modulated parameter (for example initial value for the Cutoff on the external filter device).